<!doctype html>
<html>
    <head>
        <meta charset="utf-8">
        <title>Bar3D Simplex Noise - ECHARTS-GL</title>
        <meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no">
        <meta name="apple-mobile-web-app-capable" content="yes"> <!-- Fullscreen Landscape on iOS -->
        <link rel="stylesheet" href="./common.css">
    </head>
    <body>
        <div id="main"></div>
        <script src="../node_modules/echarts/dist/echarts.js"></script>
        <script src="../dist/echarts-gl.js"></script>
        <script src="lib/jquery.min.js"></script>
        <script src="lib/dat.gui.js"></script>
        <script src="js/commonUI.js"></script>
        <script>
            var chart = echarts.init(document.getElementById('main'), null, {
                devicePixelRatio: 1
            });
            var img = new Image();
            var canvas = document.createElement('canvas');
            var ctx = canvas.getContext('2d');

            var config = {
                scale: 0.25
            };

            chart.setOption({
                tooltip: {},
                backgroundColor: '#000',
                xAxis3D: {
                    type: 'value'
                },
                yAxis3D: {
                    type: 'value'
                },
                zAxis3D: {
                    type: 'value',
                    min: 0,
                    max: 100
                },
                grid3D: {
                    show: false,
                    viewControl: {
                        alpha: 70,
                        beta: 0
                    },
                    postEffect: {
                        enable: true,
                        bloom: {
                            // intensity: 0.2
                        },
                        screenSpaceAmbientOcclusion: {
                            enable: true,
                            intensity: 0
                        }
                        // depthOfField: {
                        //     enable: true,
                        //     blurRadius: 4,
                        //     fstop: 10
                        // }
                    },
                    boxDepth: 100,
                    boxHeight: 20,
                    environment: 'none',
                    light: {
                        main: {
                            shadow: true,
                            intensity: 2
                        },
                        ambientCubemap: {
                            texture: 'asset/canyon.hdr',
                            exposure: 2,
                            diffuseIntensity: 0.2
                        }
                    }
                }
            })

            function updateData(pixelData, width, height) {
                console.time('update');
                var data = new Float32Array(pixelData.length / 4 * 3);

                var off = 0;
                for (var i = 0; i < pixelData.length / 4; i++) {
                    var r = pixelData[i * 4];
                    var g = pixelData[i * 4 + 1];
                    var b = pixelData[i * 4 + 2];

                    var lum = (0.2125 * r + 0.7154 * g + 0.0721 * b);
                    lum = (lum - 125) * config.scale + 50;
                    data[off++] = i % width;
                    data[off++] = height - Math.floor(i / width);
                    data[off++] = lum;
                }

                chart.setOption({
                    series: [{
                        type: 'bar3D',
                        shading: 'realistic',
                        dimensions: ['x', 'y', 'z'],
                        encode: {
                            x: 'x',
                            y: 'y',
                            z: 'z'
                        },
                        realisticMaterial: {
                            roughness: 0.4
                        },
                        barSize: 0.8,
                        silent: true,
                        itemStyle: {
                            color: function (params) {
                                var i = params.dataIndex;
                                var r = pixelData[i * 4] / 255;
                                var g = pixelData[i * 4 + 1] / 255;
                                var b = pixelData[i * 4 + 2] / 255;
                                var lum = (0.2125 * r + 0.7154 * g + 0.0721 * b);
                                r *= lum * 2;
                                g *= lum * 2;
                                b *= lum * 2;
                                return [r, g, b, 1];
                            }
                        },
                        data: data
                    }]
                });

                console.timeEnd('update');

            }

            img.onload = function () {
                var width = canvas.width = img.width / 2;
                var height = canvas.height = img.height / 2;
                ctx.drawImage(img, 0, 0, width, height);
                var imgData = ctx.getImageData(0, 0, width, height);

                updateData(imgData.data, width, height);

                var gui = new dat.GUI();
                gui.add(config, 'scale', 0, 1).onFinishChange(function () {
                    updateData(imgData.data, width, height);
                })
            }

            img.src = 'asset/sample.jpg';

            window.onresize = chart.resize;
        </script>
    </body>
</html>